If I use The Mimeoplasm and target Clone as the base creature (And for the sake of argument Death's shadow for the counters because why not?)
Would the clone still be able to clone a creature on the battlefield or would the initial effect (In this case entering the battlefield) have already passed?
If you bring The Mimeoplasm onto the battlefield as a Clone that isn't a copy of anything (and with thirteen +1/+1 counters on it, which is what Death's Shadow's power is in the graveyard or in exile irrespective of any player's life total [C.R. 611.3b, 113.6; see also this thread]), The Mimeoplasm will thus acquire Clone's copiable values, including the ability "You may have [this creature] enter the battlefield as a copy of any creature on the battlefield" (C.R. 706.2, 207.1). This ability's effect now applies and you may have The Mimeoplasm enter the battlefield as a copy of any creature on the battlefield (C.R. 616.1e).
Would the clone still be able to clone a creature on the battlefield or would the initial effect (In this case entering the battlefield) have already passed?